Integral foamed plastic sliding bearings

Abstract

Sliding bearings of all types, including axial, radial, and linear bearings and combinations thereof, are described which are composed of integral foamed molded plastic by processes known in the art per se to provide unitary bearing structures having surface and/or interior portions of hard material and surface and/or interior portions of porous material, said porous material being saturated with a lubricant and acting to release said lubricant to a sliding bearing.

What is claimed is: 
     
       1. A linear sliding bearing supporting a carriage for longitudinal movement relative to a guide with a groove, said sliding bearing comprising a pair of elongated rod members, each rod member made of a foamed plastic material consisting of at least one homogeneous liquid impermeable hard and rigid peripheral surface shell portion of generally L-shaped configuration and a porous core portion filled with a lubricant confronting and engaging the sidewall and bottom of the groove of said guide, said elongated rod members mounted so that the hard rigid peripheral surface portion engages the carriage and provides a physical support for maintaining the carriage in a predetermined spaced relation to the guide. 
     
     
       2. A unitary, one-piece radial sliding bearing supporting a rotatable shaft in the opening of the housing comprising a single, one-piece annular member in the annular space between the housing and shaft and made of a foamed plastic material consisting of at least one homogeneous, liquid impermeable hard and rigid peripheral surface shell portion of U-shaped configuration and at least one porous core portion of the same material filled with a lubricant, said sliding bearing adapted to be mounted between said housing and shaft so that the hard and rigid peripheral surface shell portion seats in said housing and the porous portion confronts the peripheral surface of the shaft, said shell being partially separated from said porous core in the area where it engages the shaft to provide improved resiliency and lubricant sealing, said outer shell providing a physical support for maintaining the members in a predetermined spaced relation. 
     
     
       3. A unitary, one-piece radial sliding bearing supporting a rotatable shaft in the opening of the housing comprising a single, one-piece annular member in the annular space between the housing and shaft and made of a foamed plastic material consisting of at least one homogeneous, liquid impermeable hard and rigid peripheral surface shell portion and a porous core portion of the same material filled with a lubricant and encapsulated in said shell, said sliding bearing adapted to be mounted between said housing and shaft so that the hard and rigid peripheral surface shell portion seats in said housing, the shell having a pair of circumferentially extending lips projecting inwardly to engage the shaft at axially spaced locations and define therebetween a chamber, means defining a plurality of circumferentially spaced openings in said shell to permit lubricant to flow from said core to said chamber.